Lubricating oil



Patented June 22, 1943 um'rso STATE LUBRICATIN G OIL Rush F. McClearyand Stiles M. Roberts, Beacon, N. Y., assignors, by mesne assignments,to The Texas Company, New York, N. Y.,-a corporation of Delaware NoDrawing. Application May 13, 1941,

- Serial N0. 393,244

22 Claims.

This invention relates to an improved lubricating oil adapted for use ininternal combustion engines and particularly to a lubricating oil havingone or more additive ingredients incorporated therein.

It is generally conceded that in the recent development of internalcombustion engines, and particularly engines designed for heavy dutyservice, the increase in operating temperatures, together with thereduction of clearances and the use'of hard bearing alloys, such ascopperlead, cadmium silver, etc., have set up such severe operatingconditions as to necessitateanimprovement in the highly solvent-refinedmineral oils refined for use as lubricants. These rigorous operatingconditions which are most prevalent in Diesel and gasoline engines usedin heavy duty bus and tractor service, where the piston ringtemperatures range from approximately 425 to 650 F. and pressures fromthe oxidizing combustion gases are as high as 750 to 1150 pounds persquare inch, have seriously accentuated such problems as corrosion,oxidation and resin formation in the solvent-refined mineral lubricatingoils with the resultant deleterious efiect on the efliciency of theengines. The nature and extent of these problems depends upon theconditions of operation of the particular engine type, the type andextent of refining of the base oil used, and numerous other factors. .1

The tendency of mineral lubricating oils to deposit gums, resins, soot,and varnish-like materials about the valves, rings, pistons, cylindersand other engine parts can be largely overcome by the addition ofcertain types of additive ingredients which possess detergent qualitieswhen dissolved or dispersed in lubricating oils. By

detergent property is meant not. only that property which aids indispersing, removing or purging foreign materials which accumulate onthe surface of the engine parts but also that property which preventsthe accumulation or deposition of such materials asdistinguished fromsolvent action upon those accumulations or deposits.

In addition thereto, the added tendency of these oils to corrode themetal surfaces with which the lubricating oil comes in contact may[beovercome or reduced by the addition of additive components whichpossess anti-oxidant oranti-corrosive properties when dissolved ordispersed in mineral lubricating oils. These antioxidant oranti-corrosive properties are meant to include all such properties whicheffect a reduction or elimination of weight loss of the lubricatingsurfaces, particularly bearing surfaces, which result from the corrosiveaction of the mineral lubricating oil.

It is the object of the present invention to provide a mineral oilcomposition whichpossesses the above-mentioned detergent andanti-oxidant or anti-corrosive properties by incorporating in a amineral lubricating oil a novel additive ingredient of multi-functionalactivity.

A further object of this invention is to provide a mineral oilcomposition possessing detergent properties and enhanced anti-oxidant oranticorrosive properties by combiningwith the above-.

mentioned multi-functional additive an auxiliary additive ingredient andincorporating the combination in a lubricating mineral oil.

The invention is based upon the discovery of a novel class ofmulti-functional additives which may bebroadly described as oil-solubleor oilmiscible hydroxy aromatic or mercapto aromatic methylenethioethers and/or the metal derivatives thereof. It has been found thatwhen small proportions of a compound within the scope of the abovegeneral class are blended with a mineral lubricating oil, a mineral oilcomposition is formed possessing excellent detergent and antioxidant oranti-corrosive properties. The compounds of the present invention may bedescribed as that'class of aromatic compounds which contain at least oneradical of the type --CH.2-SR1 attached to a nuclear carbon atom and atleast one hydroxy (OH) or sulfhydryl (SH) radical or their metal salts.Specifically these compounds may be represented by the followingstructural formula .in which B may be a hydrogen, 'alkyl, aryl,cyclomatic nucleus not satisfied by other substituents or residualhydrogen. The aromatic nucleus diagrammatically shown may besubstitutedby a naphthenyl, anthracyl or any other condensed aromatic nucleus. Thepositions of the substituents are purely diagrammatic and may beconnected to any position in the aromatic nucleus. The metal derivativesof this class of compounds which are formed by the substitution of the're-' 1 placeable hydrogen in the hydroxyl radical (OH) or thesulfhydryl radical (SH) include any of the following metals: sodium,potassium, lithium, calcium, barium, strontium, magnesium, zinc,

iron, cobalt, nickel, aluminum, manganese, and

chromium.

sulfur, oxygen, or nitrogen derivatives. X

- n=i,y=2, z -3 Tri (cyclohexylthiomethyl) phenol n- 3,u=l, z=2 1 Di(cyclohemlthiomethyl) pyrogallol '4 nae-=2 Di (cyclohexylthiomethyi)hydroquinone 'R=al7cyl,-R1=cralkyl n, y, z==i Benzylthiomethyl octylphenol a. y=l, z= 2 Di (benzylthiomethyl) octyl phenol 73:1, 3i=2, 2==1Benzylthiomethyl dioctyl pheno n=1, 2!, Z=2 Di (benzylthiomethyl)dioctyl phenol n=2. 3 e=1 a Benzylthiomethyl undecyl hydroquinone 12:2,y=l, z=2' Di (benzylthiomethyl) undecyl hydroquinone Di(naphthenylthiomethyl) 'n'ndecyl resorcinol R=hydrogem R1=naichthenyl In= 11= .z=2' Di (naphthenylthiomethyl) phenol n=l, i!=2, z=3 Tri(naphthenylthiomethyl) phenol y: 2:2 Di (naphthenylthiomethyl)resorcinol R=tertiary aminomethyl, R1=alkyl n=1, y=1, z=2 Di(amylthiomethyl) dimethylaminomethyl phenol n=2,y=1. z=1 Amylthiomethylmorpholinomethyl resorclnol The general class of compounds representedby the foregoing may be prepared by the following reaction:

OHr-N-(CH:)2+H i cars-main.

They may also be prepared by the interaction or alkylated phenol.formaldehyde and mereap-l tana'sshown:

(2) on on wever, any of the other classical method.

of synthesis may be used. and the following ex amples are mentioned asillustrating one method of preparation:

. a. LEI

-- 1m preparing amylthiomethyl octyl phenol according to reaction No. 1,196 grams of dimethylnomethyl octyl phenol and 210 grams of amylmercfiptan were intimately mixed with agitation and refluxed ior35hours. Dimethylamine was given oii and after the evolution was completethe reaction mixture was transferred to a distilling flask and distilledunder vacuum. The product was collected at 150 to 190 C. at threemillimeters pressure. The resulting amylthiomethyl octyl phenol wasobtained as a clear, light yellow liquid (B. P. 160-170 C. at'threemillimeters mercury) and analyzed 9.3% sulfur.

65 grams of amylthiomethyl octyl phenol, '22; grams of barium hydroxide,and 250 cc. of tolucm were intimately mixed under agitation and refluxedunder automatic water separator until no more water was eliminated fromthe reaction. Filter-cel was added to the reaction mixture and theexcess barium hydroxide filtered out. The filtrate was freed of tolueneby heating under vacuum and the resulting 1 barium amylthiomethyl octylphenolate was obtained as a clear, brittle, light-brown solid, which wasdissolved in an equal weight of'lubricating oil. The concentrateanalyzed 8.3% barium and 4.35% sulfur.

A partially substituted product was obtained byreacting tri(dimethylaminomethyl) phenol under mild conditions. in accordance withreaction No. 1. In this reaction 265 grams of tri (dimethylaminomethyl)phenol, 500 grams of amyl mercaptan, and 400 cc. of toluene were stirredtogether and refluxed for hours. Di-

' methylamine was given ofi and after the evolu- Amylthiomethyldi(dimethylaminoethyl) phenol tion was complete the toluene and excessamyl mercaptan were distilled ofi at atmospheric pressure and a smallintermediate fraction was collected which boiled up to 15Q"C. at 10millimeters mercury. The residual amylthiomethyl di(dimethylaminomethyl) phenol appeared as a light brown oil and analyzed7.42% sulfur and 9.02% nitrogen.

The proportions of these multi-functional additives added to a minerallubricating oil may vary between 0.1 and 5.0% by weight, depending uponthe particular base oil used and the type r of engine and serviceinvolved. However, the

range and proportions between 0.25 and 2.0% by weight have been found tobe particularly effective in imparting excellent detergent andanti-corrosive properties to the mineral lubricating oil.

An additional feature of the present invention is a combination of theforegoing multi-functional additives with an auxiliary additive tofurther enhance the anti-oxidant or anti-corrosive properties of themineral oil composition with which the additives are used in certainDiesel and gasoline engines designed for heavy duty service. A higherdegree of anti-oxidant -or anti-corrosive properties is desired and itis .for this purpose that an auxiliary additive ingredient is added tothe compounds aforementioned. 1

The class of compounds which may be used to impart the additionalanti-corrosive propertiesmay be any one of the generally acceptedsulfurized anti-corrosives. Among the particularly effective sulfurizedanti-corrosive compounds found suitable for purposes of the inventionare the sulfurized esters of oleic acid, such as sulfurized ethyloleate; sulfurized highboiling gasoline "polymers, such as thesulfurized clay tower polymers; sulfurized fatty oils, such assulfurized sperm oil; sulfurized wax compounds, such as sulfurizedparaffin wax; sulfurized resins, such as sulfurized abietene; sulfurizedtall oil; and sulfurized terpene hydrocarbons, such as the sulfurizedterpinolenes and isomers thereof whichare disclosed and claimed in thecopending application of Knowles, McCoy and Patterson, Serial No.391,468, filed May ,2, 1941. The amount of sulfurized compound added tothe mineral lubricating oil in combination with the multi-functionaladditive is usual y within the proportion range of 0.5 and 5.0% byweight and preferably between 1.0% and 3.0%, depending upon the type oflubricating oil used.

These sulfurized auxiliary additives may be prepared in accordance withthe copending applications of Knowles and McCoy,-Serial Nos. 358,876;358,877 and 358,878, respectively, all

filed September 28, 1940, wherein a light-colored sulfurized material isprepared by the direct action of sulfur on the material to be sulfurized.at approximately 300 F. in the presence of water and under pressure ofhydrogen sulfide. This pressure, which is at least 50 pounds per squareinch, is maintained until all the free sulfur has entered intocombination which usually requires from one-half to three hours. Thesulfurized products formed by this process are directly soluble in amineral oil and possess the added advantage in that the reaction productis a light-colored compound as against the usu-, ally dark-coloredsulfurized compounds.

As illustrative of the anti-corrosive properties of a lubricating oilcontaining either or both of the aforementioned class of compounds, theresults of the following empirical tests ar presented. Av copper-leadbearing specimen .'encasedin a special non-wear bushing and rotatablymounted on a stainless steel shaft, was

The tested oil was heated to a controlled temperature of either. 250Fyor 350 F. and con-- tinuously circulated between the bearing specimenand the shaft for 10 hours. The bearing specimen was weighed before thetest and after the 10 hour period and the loss in weight recorded inmilligrams. Two reference oils were usedin this test and will bereferred to as Both a of these reference oils were solvent-refined, de-

Reference oil A" and Reference oil B.

\ immersed in a glass pot of the oil to be tested.

The results of two runs at both 250 F. and 350' F, are presented:

Bmamc CORROSION COPPER Lean (10 Hours) Loss of weight in ms.

Oil tested 250 F. 850 F.

Reference oil A 4, 6 142, 177 Reference oil B 4, 5 167, 199 Referenceoil B+0.5% emylthiomethyl octyl phenol l, 2 20, 51 Reference oil B+0.5%amylthiomethyl di (dimethylaminometh l) henol 0, 0 15,35 Reference oilA+0.6% um amylthiomethyl octyl phenolate 0, l 138, 161 Reference oilA+0.5% barium amylthiomethyl octyl phenolate+3.0% sulfurized sperm oill, l 46, 40 Reference oil A+0.5% barium amylthiomethyl octylpbenolate+1.0% sulfurized terpinolene 0,1 0, 0 Reference oil A+0.5%barium amylthiomethyl octyl phenolate+3.0% sulfurized clay towerpolymers 2, 0 l, 0 Reference oil A+0.5% barium amylthiomethyl octylphenolete+2.0% sulfurized ethyl oleate l, 2 3,2

An illustration of the detergent properties of the additives of thpresent invention may be shown by the results of an empirical test whichwas designed to indicate the performance of the additives in preventingthe accumulation or deposition of varnish or lacquer deposits on theengine parts. This test is carried out in a single crankcase ventilationof 0.4 cubic feet of air per minute. At the end of this period theengine was, dismantled, the piston removed and examined, the amount ofvarnish depoisted upon the piston determined, and the oil classifiedaccording to a visual classification of A, B, C. D and E (A=clean;B=light varnish; C=medium varnish; D=heavy varnish; and E=very heavyvarnish). The following results were obtained with a solvent-refined,dewaxed Mid-Continent lubricating oil of an SAE 20 grade as thereference oil, and compared with the reference oil containing theproposed additive:

Leu'son Enema Vmuusn Tss'r vention under actual operating conditions, aspecial test was devised which is a modification of the test describedin 9. Diesel Lubricant Test Manual, Laboratory Test No. 1, put out bythe Caterpillar Tractor Company. This test was carried in a singlecylinder Diesel engine operating at 900 R. P. M. with a water Jackettemperature of 175 F., and run continuously for periods of and 240hours, or until rings are stuck, as indicated by the increase in blowby.

- ing of hydrox and fresh oil added thereto.

120 and 240 hour runs the eng examined and any carbonaceous deposits,lacquer formation, or corrosion characteristics noted. In the presentinstance the reference oil used was a solvent-refined, dewax I I I II328,876-

The crankcase oil was drained am d hours At the end of the me wasthoroughly ed Mid-com I tinent lubricating oil of SAE grade:

mineral lubricating oil containing a mu amount of a compound or thewherein R is a radical selected from the "group The multi-functionaladditives of the present invention may further be used in combinationwith other additive ingredients such as pour point depressors, oilinessagents, extreme pressure agents, blooming agents, viscosity indeximproving agents, color stabilizers, etc., Without departing from thspirit of the invention.

Obviously many modifications and variations of the invention, ashereinbefore set forth, may be made without departing from the spiritand scope thereof and therefore only such limitations should be imposedas are indicated in the appended claims.

We claim:

1. An improved lubricating oil comprising a therein a small proportionof an aromatic methylene thioether containing at least one substituentlinkedto an aromatic nucleus selected from the group consisting ofhydroxyl and sulfhydryl radicals and metal salts thereof.

2. An improved lubricating oil adapted for use in internal combustionengines, comprising a mineral lubricating oil containing a small amountof a compound of the following general formula .consisting of hydrogen,alkyl, aryl, cycloalkyl,

aralkyl and naphthenyl radicals, R1 is a radical selected from the groupconsisting of alkyl, aryl, cycloalkyl, aralkyl and naphthenyl radicals,X is a substituent selected from the group consistyl and sulfhydrylradicals and metal salts thereof, and n, y and z are integers of atleast 1. I

3. An improved lubricating oil adapted for use in internal combustionengines, comprising a mineral lubricating oil having incorporatedvbarium in. 1 Engine pert Reference oil mg g g 5 mhwolm Y t Piston crown:

120 hours. Normal Normal. PMMO lligursuu; do I D0. 4 011 I S! 12c heirsNos, 3 and 4 slight lacquer; Noao and 6 Nos. 1, 2 and 3 clean; No. 4heavy lacquer;

iilIudgosldlggsittivggh No. 5 stichng and No. :ulacquer; No. 6 lightlacquer; no

0.6 s c ring 240 hours Nos, 1, 2 and 3 clean? but No. 1 ring Nos. 1, 2an 3 clean; Nos. 4 and 5 heavy stuck in ring groove; Nos. 4, 5 and 6lacquer; No. 6 lacquer; no ring sticking show lacquer on top of ring andsigns oi Rm sticking.

g grooves: -h All 1 No. 1 trace deposi Nos. 2 and 3 heavy c Ban lacquer;No.4 uenNo. fiiight lacquer;

. No. 6 heavy-v 240-hours No. 1 hard carbon buildup; Nos. 2, 4, 6 Nos. 1and 2 trace deposit; Nos. 3, 4 and 5 Pi km and 6 black lacquer; No. 3trace of lacquer. heavy lacquer; No. 6 lacquer.

t n a i 20 hours t 1" ring of heavy brown varnish and other Trace 01varnish on thrust side and 3" spotted areas; 4" dark brown v brownvarnish formation along axis oi formation extending along axis ofpiston. anti-thrust side. 240 hours 2" ring of brown varnish aroundpiston Trace varnish both thrust and anti-thrust and 3" black-brownvarnish iormation sides.

along axis oi piston. Under piston deposit: 120 hours .i Trace.

Block, granular deposit Home a 120 hours. Li t ooatin oi lint siud eCovered with lint-mesh outline visible.

240 hours sui'i aoe covei ed with lint siudge, no mesh Covered withlint-mesh patternvisibie.

visible. I

consisting of hydrogen, alkyl, aryl, cycioaiiryl, aralkyl and naphthenylradicals, R1. is a radical selected from the group consisting of alkyl,aryl, cycloalkyl, aralkyl and naphthenyl radicals, X is a hydroxylradical, and n, y and z are integers of at least L 4. An improvedlubricating o l adapted for use in internal combustion engines,comprising a mineral lubricating oil containing a small amount of acompound of the'following general formula wherein R. is a radicalselected from the group consisting of hydrogen, alkyl, aryl, cycloallwl,aralkyl and naphthenyl radicals, R1 is a radical selected from the groupconsisting of allsvl, aryl, cycloalkyl, aralkyl and naphthenyl radicals,X is a metal oxide, andn, y and z are integers of at least 1.

' 5. An improved lubricating oil adapted for use in internal combustionengines, comprising a mineral lubricating 011 containing a small amountof a compound of the following general formula wherein R is a radicalselected from the group consisting of hydrogen, alkyl, aryl, cycloalkyl,aralkyl and naphthenyl radicals, R1 is a radical selected from the groupconsisting of alkyl, aryl, cycloalkyl, aralkyl and naphthenyl radicals,X is a substituent selected from the group consisting of hydroxyl andsulfhydryl radicals and meta?- salts thereof, 1: is equal to 1, and 1and z are in tegers of at least 1.

following general formula I 6. An improved lubricating oil comprising amineral lubricating oil having incorporated therein 0.1 to 5.0% byweight of an aromatic methylene thioether containing at least onesubtherein 0.25 to 2.0% by weight of an aromatic methylene thioethercontaining at least one substituent linked to an aromatic nucleusselected from the group consisting of hydroxyl and sulfhydryl radicalsand metal salts thereof.

8. An improved lubricating oil adapted for use in internal combustionengines, comprising a major proportion of a mineral lubricating oil anda minor proportion of an aromatic methylene thioether containing atleast one substituent linked to an aromatic nucleus selected from thegroup consisting of hydroxyl and sulfhydryl radicals and metal saltsthereof, and a sulfurized additive ingredient possessing anti-corrosiveproperties.

9. An improved lubricating-oil adapted for use in internal combustionengines, comprising a major proportion of a mineral lubricating oil anda minor proportion of an aromatic methylene thioether containing atleast one suhstituent linked to an aromatic nucleus selected from thegroup consisting of hydroxyl and sulfhydryl radicals and metal saltsthereof, and a sulfurized additive ingredient selected from the groupconsisting of sulfurized esters of oleic acid, sulfurized high boilinggasoline polymers, sulfurized fatty oils, sulfurized wax compounds,sulfurized resins,

sulfurized tall oil, and sulfurized terpene hydrocarbons.

10. An improved lubricating oil adapted for use in internal combustionengines comprising a mineral lubricating 011 containing 0.1 to 5.0% byweight of an aromatic methylene thioether containing at least onesubstituentlinked to an aromatic nucleus selected from the groupconsisting of hydroxyl and sulfhydryl radicals and metal salts thereof,and 0.5 to 5.0% by weight of a sulfurized additive ingredient possessinganticorrosive properties.

11. An improved lubricating oil adapted for use in internal combustionengines, comprising a mineral lubricating oil containing 0.25 to 2.0% byweight of a compound of the following general formula selected from thegroup consisting of alkyl, aryl,

cycloalkyl, aralkyl and naphthenyl radicals, X is a substituent selectedfrom the group consisting of hydroxyl and sulfhydrylradicals and metalsalts thereof, and n, y and z are integers of at least 1, and 1.0 to3.0% by weight 'of a sulfurized additive ingredient selected from thegroup consisting of sulfurized esters of oleic acid, sulfurized highboiling gasoline polymers, sulfurized fatty oils, sulfurized waxcompounds, sulfurized resins, sulfurized tall oil, and sulfurizedterpene hydrocarbons. g I

. 12. An improved lubricant comprising a mineral lubricating oil and asmall proportion of a compound of the following general formula:

1 12, wherein X is an hydroxyl radical.

14. An improved lubricant according to claim 12, wherein X is a-metaloxide.

15. An improved lubricant comprising a mineral lubricating oil and asmall proportion of a I compound of the following general formula:

of at least 1.

16. An improved lubrmant as claimed in claim 15, wherein n is 1, 11 is3, and z is 2.

17. An improved lubricant as claimed in claim 15, whereinnis1,1Iis2andzis3.

'18. An improved lubricant comprising a mineral lubricating oil havingincorporated therein a small proportion of an alkyl phenol methylenethio ether.

19. An improved lubricant comprising a minerallubricating oil havingincorporated therein a small proportion of a metal salt of an alkylphenol methylene thio ether.

20.- An improved lubricant comprising a mineraloil having incorporatedtherein a small proportion of barium amylthiomethyl phenolate.

21. An improved lubricant comprising a minoctyl eral lubricating oilhaving incorporated therein a Q small proportion of di (amylthiomethyl)phenol.

22. An improved lubricant comprising a mineral lubricating oil havingincorporated therein a small proportion of amylthiomethyl di(dimethylaminomethyl) phenol.

RUSH F. MccmARY. s'rnns M. ROBERTS.

